Recently, an electromagnetic cooker which does not generate flames has been used in a household, a place that serves food and drink such as a restaurant or the like for cooking foods or heating cooked foods from a viewpoint of safety, cleanliness, convenience and economy. The electromagnetic cooker heats food in a container such that, when a container for an electromagnetic cooker made of steel or stainless steel is placed on the electromagnetic cooker, an eddy current is generated in a bottom portion of the container for an electromagnetic cooker due to lines of magnetic force from an electromagnetic coil, and this eddy current induces Joule heat which is used for heating the food in the container.
Further, by making use of such a principle, a large number of electromagnetic induction rice cooker (IH rice cookers) has been commercialized. As an instant-food-use container which enables heating thereof using an electromagnetic cooker by making use of such a principle, there has been proposed a container for an electromagnetic cooker such as an instant-food-use container which enables direct heating of a container which packs noodles such as Chinese noodles, buckwheat noodles or Japanese noodles, fried noodles therein by an electromagnetic cooker (patent document 1) or an aluminum-foil-made food container which enables heating of a container by an electromagnetic cooker (patent document 2).
Still further, there have been also proposed a container which is used in common for an electromagnetic cooker and an microwave oven and is manufactured by taking the separation of parts of the container by kinds, incineration of the container and recycling of a magnetic body which constitutes a heat generating body after use into consideration (patent document 3) and a container for an electromagnetic cooker which allows an aluminum foil to generate heat (patent document 4).    [Patent document 1] JP-A-2000-272676    [Patent document 2] JP-A-2002-51906    [Patent document 3] JP-A-2002-177149    [Patent document 4] JP-A-2003-325327